Continuous glucose monitoring in noninsulin-treated type 2 diabetes: A critical review of reported trials with an updated systematic review and meta-analysis of randomised controlled trials

Abstract

Aims: We aimed to review the observational and randomised clinical trial evidence and provide pragmatic recommendations for using continuous glucose monitoring (CGM) in individuals living with noninsulin-treated type 2 diabetes (T2DM). Materials and Methods: We first undertook a narrative review of observational studies that enrolled noninsulin-users or mixed populations of noninsulin and insulin-users with T2DM as well as randomised controlled trials (RCTs) that enrolled mixed populations with T2DM. We then performed a systematic review of the RCTs that specifically enrolled noninsulin-treated populations with T2DM and compared CGM to BGM/usual care. A meta-analysis of glycaemic outcomes was conducted with predefined subgroups based on CGM type. Results: RCTs in mixed populations and observational studies demonstrated a largely consistent benefit of CGM on glycaemic and nonglycaemic outcomes with cost effectiveness and reduced healthcare resource utilisation. The meta-analysis of RCTs in noninsulin users included 8 studies encompassing 541 participants, among whom 297 (55%) were assigned to the CGM group. CGM was associated with significantly reduced HbA1c (weighted mean difference [WMD] −0.37%; 95% CI −0.49, −0.24; p < 0.00001; I2 = 0%), increased % time in range (WMD 8.84; 95% CI 4.62, 13.06; p < 0.0001; I2 = 0%) and lower % time above range (WMD −8.14; 95% CI −12.66, −3.63; p = 0.0004; I2 = 0%). There were no significant subgroup differences. Conclusions: CGM use in noninsulin-treated individuals living with T2DM was associated with improved glycaemic outcomes and patient experience, reduced health care resource utilisation, and acceptable cost-effectiveness. These findings provide additional evidence to support CGM use among people living with T2DM who are not using insulin therapy.